<template>
  <div class="">
    <router-link tag="div" to="/" class="header-abs">
      <i class="iconfont header-back">&#xe624;</i>
    </router-link>
    <div class="header-fixed" v-show="!showAbs" :style="opacityStyle">
      <router-link to="/">
        <i class="back-icon iconfont ">&#xe624;</i>
      </router-link>
      景点详情

    </div>
  </div>
</template>

<script type="text/ecmascript-6">
export default {
  data () {
    return {
      showAbs: true,
      opacityStyle: {
        opacity: 0
      }
    }
  },
  methods: {
    handleScroll () {
      const top = document.documentElement.scrollTop
      if (top > 60) {
        let opacity = top / 140
        opacity = opacity > 1 ? 1 : opacity
        this.opacityStyle = {
          opacity
        }
        this.showAbs = false
      } else {
        this.showAbs = true
      }
    }
  },
  activated () {
    window.addEventListener('scroll', this.handleScroll)
  },
  deactivated () {
    window.removeEventListener('scroll', this.handleScroll)
  }

}
</script>

<style scoped lang="stylus">
@import '~styles/varibles.styl'

  .header-abs
    position absolute
    left .2rem
    top .2rem
    width 0.8rem
    height 0.8rem
    line-height 0.8rem
    text-align center
    background rgba(0,0,0,0.8)
    border-radius 50%
    .header-back
      color #fff
      font-size 0.4rem
  .header-fixed
    z-index 2
    position fixed
    top 0
    left 0
    right 0
    overflow hidden
    height $headerHeight
    line-height $headerHeight
    text-align center
    color #fff
    background $bgColor
    font-size 0.32rem
  .back-icon
    position absolute
    top 0
    left 0
    width 0.64rem
    font-size 0.4rem
    color #fff
</style>
